Department of General Surgery, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Clin Transl Med. 2022 May;12(5):e849. doi: 10.1002/ctm2.849.
Sepsis remains the most lethal infectious disease and substantially impairs patient prognosis after liver transplantation (LT). Our previous study reported a role of the pannexin 1 (PANX1)-interleukin-33 (IL-33) axis in activating innate immunity to protect against methicillin-resistant Staphylococcus aureus infection; however, the role of PANX1 in regulating adaptive immunity in sepsis and the underlying mechanism are unclear. In this study, we examined the role of the PANX1-IL-33 axis in protecting against sepsis caused by a gram-negative bacterial infection in an independent LT cohort. Next, in animal studies, we assessed the immunological state of Panx1 mice with lipopolysaccharide (LPS)-induced endotoxemia and then focused on the cytokine storm and regulatory T cells (Tregs), which are crucial for the resolution of inflammation. To generate liver-specific Panx1-deficient mice and mimic clinical LT procedures, a mouse LT model was established. We demonstrated that hepatic PANX1 deficiency exacerbated LPS-induced endotoxemia and dysregulated the immune response in the mouse LT model. In hepatocytes, we confirmed that PANX1 positively regulated IL-33 synthesis after LPS administration. We showed that the adenosine triphosphate-P2X7 pathway regulated the hepatic PANX1-IL-33 axis during endotoxemia in vitro and in vivo. Recombinant IL-33 treatment rescued LPS-induced endotoxemia by increasing the numbers of liver-infiltrating ST2 Tregs and attenuating the cytokine storm in hepatic PANX1-deficient mice. In conclusion, our findings revealed that the hepatic PANX1-IL-33 axis protects against endotoxemia and liver injury by targeting ST2 Tregs and promoting the early resolution of hyperinflammation.
脓毒症仍然是最致命的传染病,极大地影响肝移植(LT)后的患者预后。我们之前的研究报告了连接蛋白 1(PANX1)-白细胞介素 33(IL-33)轴在激活固有免疫以抵抗耐甲氧西林金黄色葡萄球菌感染中的作用;然而,PANX1 在调节脓毒症中的适应性免疫及其潜在机制尚不清楚。在这项研究中,我们在独立的 LT 队列中研究了 PANX1-IL-33 轴在保护革兰氏阴性菌感染引起的脓毒症中的作用。接下来,在动物研究中,我们评估了脂多糖(LPS)诱导的内毒素血症中 Panx1 小鼠的免疫状态,然后重点研究了细胞因子风暴和调节性 T 细胞(Tregs),它们对于炎症的消退至关重要。为了生成肝脏特异性 Panx1 缺陷小鼠并模拟临床 LT 程序,建立了小鼠 LT 模型。我们证明了肝 PANX1 缺乏加剧了 LPS 诱导的内毒素血症,并调节了小鼠 LT 模型中的免疫反应。在肝细胞中,我们证实 PANX1 在 LPS 给药后可正向调节 IL-33 的合成。我们表明,三磷酸腺苷-P2X7 途径在体外和体内调节内毒素血症期间肝脏的 PANX1-IL-33 轴。重组 IL-33 治疗通过增加肝浸润性 ST2 Tregs 的数量并减轻肝 PANX1 缺陷小鼠中的细胞因子风暴,挽救了 LPS 诱导的内毒素血症。总之,我们的研究结果表明,肝脏 PANX1-IL-33 轴通过靶向 ST2 Tregs 并促进过度炎症的早期缓解来保护内毒素血症和肝损伤。